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title="使用 FormBuilder、表单组和表单数组创建响应式表单。" target="_self"><span>响应式表单</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/forms" title="使用指令和 Angular 模板语法创建模板驱动表单。" target="_self"><span>模板驱动表单</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/form-validation" title="验证用户的表单输入" target="_self"><span>表单验证</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dynamic-form" title="使用 FormGroup 渲染动态表单。" target="_self"><span>动态表单</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div 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target="_self"><span>RxJS 库</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/observables-in-angular" title="" target="_self"><span>Angular 中的可观察对象</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/practical-observable-usage" title="" target="_self"><span>用法实战</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/comparing-observables" title="" target="_self"><span>与其它技术的比较</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular 中的模块" aria-pressed="false"><span>NgModules</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodules" title="使用 NgModule 让你的应用更高效" target="_self"><span>NgModule 简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodule-vs-jsmodule" title="JavaScript 模块和 NgModule 之间的差异" target="_self"><span>JS 模块 vs NgModule</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/bootstrapping" title="告诉 Angular 如何在根 &quot;AppModule&quot; 中构造和引导应用。" target="_self"><span>应用的根模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/frequent-ngmodules" title="介绍最常用的 NgModule" target="_self"><span>常用模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/module-types" title="介绍特性模块的几种类型" target="_self"><span>特性模块的分类</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/entry-components" title="关于 Angular 中入口组件的一切" target="_self"><span>入口组件</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/feature-modules" title="创建特性模块，以组织你的代码" target="_self"><span>特性模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/providers" title="服务提供商与 NgModule" target="_self"><span>服务提供商</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/singleton-services" title="创建单例服务" target="_self"><span>单例服务</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/lazy-loading-ngmodules" title="惰性加载模块，以提高应用的性能" target="_self"><span>惰性加载的特性模块</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/sharing-ngmodules" title="共享 NgModule 让你的应用现代化。" target="_self"><span>共享 NgModule</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodule-api" title="理解 NgModule 的那些细节。" target="_self"><span>NgModule API</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ngmodule-faq" title="回答关于 NgModules 的常见问题。" target="_self"><span>NgModule 常见问题</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="依赖注入：创建并注入各种服务。" aria-pressed="false"><span>依赖注入</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection" title="Angular 的依赖注入系统能够为 Angular 创建的类创建并交付它们所依赖的服务。" target="_self"><span>Angular 依赖注入</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/hierarchical-dependency-injection" title="与组件树平行的注入器树，并支持嵌套的依赖。" target="_self"><span>多级注入器</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection-providers" title="各种提供商类型的更多知识。" target="_self"><span>DI 提供商</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection-in-action" title="依赖注入的使用技巧" target="_self"><span>DI 实战</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/dependency-injection-navtree" title="使用注入器树来查找父组件。" target="_self"><span>浏览组件树</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/http" title="通过 HTTP 协议与远程服务器对话。" target="_self"><span>HttpClient</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/router" title="揭示如何通过 Angular 路由进行基本的屏幕导航。" target="_self"><span>路由与导航</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular 动画系统指南" aria-pressed="false"><span>动画</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/animations" title="Angular 动画的基础技术。" target="_self"><span>简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/transition-and-triggers" title="转场与触发器的高级技术。" target="_self"><span>转场与触发器</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/complex-animation-sequences" title="复杂的 Angular 动画序列。" target="_self"><span>复杂序列</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/reusable-animations" title="创建可复用的动画。" target="_self"><span>可复用动画</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/route-animations" title="为路由提供转场动画。" target="_self"><span>路由转场动画</span></a></div></aio-nav-item></div></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="把 Angular 用到你的实际工作中的一些技巧" aria-pressed="false"><span>其它技术</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/security" title="Angular 应用开发中的安全技术。" target="_self"><span>安全</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/i18n" title="把应用模板中的文本翻译成多种语言。" target="_self"><span>国际化（i18n）</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/accessibility" title="设计能被所有用户访问的应用" target="_self"><span>无障碍（a11y）</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="Angular Service Worker: 控制应用资源的缓存。" aria-pressed="false"><span>Service Worker 与 PWA</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-intro" title="Angular 对 Service Worker 的实现提升了慢速或不稳定的网络连接下的用户体验。" target="_self"><span>简介</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-getting-started" title="在 CLI 项目中启用 Service Worker，并在浏览器中查看效果。" target="_self"><span>快速上手</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/app-shell" title="在 CLI 项目中启用应用外壳。" target="_self"><span>应用外壳</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-communications" title="那些能让你和 Angular 的 Service Worker 通讯的服务类。" target="_self"><span>与 Service Worker 通讯</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-devops" title="使用 Service Worker 运行应用、管理应用更新、调试以及杀掉正在运行的应用。" target="_self"><span>生产环境下的 Service Worker</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/service-worker-config" title="配置 Service Worker 的缓存行为。" target="_self"><span>Service Worker 配置</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/universal" title="使用 Angular Universal 在服务端渲染 HTML。" target="_self"><span>服务端渲染</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="把 AngularJS 应用增量式的升级到 Angular。" aria-pressed="false"><span>从 AngularJS 升级</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/upgrade" title="把 AngularJS 应用增量式的升级到 Angular。" target="_self"><span>升级步骤</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/upgrade-performance" title="用更灵活的方式把 AngularJS 升级到 Angular。" target="_self"><span>更关注性能的升级方式</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/ajs-quick-reference" title="学习如何把 AngularJS 的概念映射到 Angular 中。" target="_self"><span>AngularJS 与 Angular 的概念对照</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="使用共享库扩展 Angular" aria-pressed="false"><span>开发 Angular 库</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/libraries" title="理解何时以及如何使用和创建库。" target="_self"><span>库概览</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/using-libraries" title="把已发布的库集成进你的应用中。" target="_self"><span>使用已发布的库</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/creating-libraries" title="通过创建、发布和使用你自己的库来扩展 Angular。" target="_self"><span>创建库</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="理解原理图" aria-pressed="false"><span>原理图（Schematic）</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/schematics" title="理解 Angular 如何使用原理图。" target="_self"><span>原理图概览</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/schematics-authoring" title="理解原理图的结构。" target="_self"><span>制作原理图</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/schematics-for-libraries" title="使用原理图来把你的库集成进 Angular CLI 中。" target="_self"><span>库的原理图</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/cli-builder" title="使用构建器定制 Angular CLI。" target="_self"><span>CLI 构建器</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/web-worker" title="在 Angular CLI 中使用 Web Worker。" target="_self"><span>Web Worker</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="关于构建、测试和部署的信息" aria-pressed="false"><span>开发工作流</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="理解 AOT 预先编译器。" aria-pressed="false"><span>AOT 预先编译器</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/aot-compiler" title="学习为何以及如何使用预先编译器。" target="_self"><span>预先编译</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/angular-compiler-options" title="配置 AOT 编译。" target="_self"><span>Angular 编译器选项</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/aot-metadata-errors" title="解决 AOT 编译错误。" target="_self"><span>AOT 元数据错误</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/template-typecheck" title="Angular 中的模板类型检查。" target="_self"><span>模板类型检查</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/build" title="构建应用及为应用启动开发服务器。" target="_self"><span>构建与运行</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/bazel" title="如何配置你的环境，以利用 Bazel 进行构建和测试。" target="_self"><span>使用 Bazel 进行构建</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/testing" title="测试 Angular 应用的技巧与实践。" target="_self"><span>测试</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/deployment" title="了解如何部署 Angular 应用。" target="_self"><span>发布</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-2 collapsed ng-star-inserted" title="与开发环境和工具集成起来" aria-pressed="false"><span>开发工具集成</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-2 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-3 collapsed ng-star-inserted" style="position:relative" href="guide/language-service" title="使用 Angular 语言服务加速开发。" target="_self"><span>语言服务</span></a></div></aio-nav-item></div></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="工作空间与项目的结构，及其配置文件。" aria-pressed="false"><span>配置</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/file-structure" title="Angular 工作区在文件系统中是怎样的。" target="_self"><span>项目文件结构</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/workspace-config" title="&quot;angular.json&quot; 包含供 CLI 命令使用的工作区和项目默认配置。" target="_self"><span>工作区配置</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/npm-packages" title="开发期间和运行期间所需的 npm 包的说明。" target="_self"><span>npm 包</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/typescript-configuration" title="给 Angular 开发者的 TypeScript 配置。" target="_self"><span>TypeScript 配置</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/browser-support" title="浏览器支持与腻子脚本指南。" target="_self"><span>浏览器支持</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="Angular 的版本发布实践、更新与升级。" aria-pressed="false"><span>发布信息</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/updating" title="如何把 Angular 应用和库升级到最新版本。" target="_self"><span>保持最新</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/releases" title="Angular 的版本、发布、支持、弃用策略及实践。" target="_self"><span>发布实践</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/updating-to-version-9" title="支持把你的应用从 8 升级到 9。" target="_self"><span>升级到第 9 版</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/deprecations" title="弃用的 Angular API 和特性汇总。" target="_self"><span>弃用清单</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/ivy" title="关于 Angular Ivy 的编译与渲染管道。" target="_self"><span>Angular Ivy</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="Angular 语法、编码、术语汇总。" aria-pressed="false"><span>快捷手册</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/cheatsheet" title="关于 Angular 常用编码技术的快速指南。" target="_self"><span>速查表</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/styleguide" title="写出 Angular 风格的程序" target="_self"><span>风格指南</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="guide/glossary" title="Angular 中最重要的词汇的简要定义。" target="_self"><span>词汇表</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><button type="button" class="vertical-menu-item heading level-1 collapsed ng-star-inserted" title="Angular CLI 命令参考手册。" aria-pressed="false"><span>CLI 命令</span><mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><div class="heading-children level-1 collapsed"><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli" title="CLI 工具介绍、命令、语法" target="_self"><span>概览</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/usage-analytics-gathering" title="管理员如何从用户那里收集使用情况分析。" target="_self"><span>使用情况分析</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/add" title="ng add." target="_self"><span>ng add</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/analytics" title="ng analytics." target="_self"><span>ng analytics</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/build" title="ng build." target="_self"><span>ng build</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/config" title="ng config." target="_self"><span>ng config</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/deploy" title="ng deploy." target="_self"><span>ng deploy</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/doc" title="ng doc." target="_self"><span>ng doc</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/e2e" title="ng e2e." target="_self"><span>ng e2e</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/generate" title="ng generate." target="_self"><span>ng generate</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/help" title="ng help." target="_self"><span>ng help</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/lint" title="ng lint." target="_self"><span>ng lint</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/new" title="ng new." target="_self"><span>ng new</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/run" title="ng run." target="_self"><span>ng run</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/serve" title="ng serve." target="_self"><span>ng serve</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/test" title="ng test." target="_self"><span>ng test</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/update" title="ng update." target="_self"><span>ng update</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/version" title="ng version." target="_self"><span>ng version</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-2 collapsed ng-star-inserted" style="position:relative" href="cli/xi18n" title="ng xi18n." target="_self"><span>ng xi18n</span></a></div></aio-nav-item></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="api" title="关于 Angular 中类和值的详细信息。" target="_self"><span>API 参考手册</span></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><div class="mat-divider ng-star-inserted" style="margin:4px 20px;border-top:1px solid #d3d3d3"></div></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://github.com/ng-docs/ng-docs.github.io/issues" title="github 上的中文互助问答区" target="_blank"><span>互助问答</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://material.angular.cn" title="Angular Material 组件库的中文文档" target="_blank"><span>官方 Material 组件库</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://ng.ant.design/" title="Ant Design 的 Angular 实现，服务于企业级后台产品。" target="_blank"><span>ng-zorro 组件库</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://ng.mobile.ant.design/" title="Ant Design Mobile 的 Angular 实现，服务于无线产品。" target="_blank"><span>ng-zorro mobile 组件库</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item><aio-nav-item class="ng-star-inserted"><div class="ng-star-inserted"><a class="vertical-menu-item level-1 collapsed ng-star-inserted" style="position:relative" href="https://flutter-io.cn/" title="Flutter 中文文档站" target="_blank"><span>友站：Flutter 中文</span><mat-icon role="img" class="mat-icon notranslate material-icons mat-icon-no-color ng-star-inserted" aria-hidden="true">open_in_new</mat-icon></a></div></aio-nav-item></aio-nav-menu><div class="doc-version ng-tns-c18-1"><aio-select><div class="form-select-menu"><button class="form-select-button"><span><strong></strong></span><span>stable (v9.0.0)</span></button></div></aio-select></div></div></mat-sidenav><div class="cdk-visually-hidden cdk-focus-trap-anchor" aria-hidden="true"></div><mat-sidenav-content cdkscrollable="" class="mat-drawer-content mat-sidenav-content ng-star-inserted" style="margin-left:261px"><main role="main" class="sidenav-content" id="guide-architecture-components"><aio-mode-banner></aio-mode-banner><aio-doc-viewer class=""><div style="opacity:1"><div class="github-links"><a href="https://github.com/angular/angular-cn/edit/aio/aio/content/guide/architecture-components.md?message=docs%3A%20请简述你的修改..." aria-label="提供编辑建议" title="提供编辑建议"><i class="material-icons" aria-hidden="true" role="img">mode_edit</i></a></div><div class="content"><h1 id="introduction-to-components" translation-result="on">组件简介<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#introduction-to-components"><i class="material-icons">link</i></a></h1><aio-toc class="embedded" ng-version="9.0.0-rc.11"><div class="toc-inner no-print collapsed ng-star-inserted"><button type="button" title="Expand/collapse contents" aria-label="Expand/collapse contents" class="toc-heading embedded secondary ng-star-inserted" aria-pressed="false">目录<mat-icon role="img" svgicon="keyboard_arrow_right" class="mat-icon notranslate rotating-icon collapsed mat-icon-no-color" aria-hidden="true"><svg focusable="false" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M8.59 16.34l4.58-4.59-4.58-4.59L10 5.75l6 6-6 6z"></path></svg></mat-icon></button><ul class="toc-list embedded"><li class="h2 ng-star-inserted" title="组件的元数据"><a href="guide/architecture-components#component-metadata">组件的元数据</a></li><li class="h2 ng-star-inserted" title="模板与视图"><a href="guide/architecture-components#templates-and-views">模板与视图</a></li><li class="h2 ng-star-inserted" title="模板语法"><a href="guide/architecture-components#template-syntax">模板语法</a></li><li class="h3 secondary ng-star-inserted" title="数据绑定"><a href="guide/architecture-components#data-binding">数据绑定</a></li><li class="h3 secondary ng-star-inserted" title="管道"><a href="guide/architecture-components#pipes">管道</a></li><li class="h3 secondary ng-star-inserted" title="指令"><a href="guide/architecture-components#directives">指令</a></li></ul><button type="button" title="Expand/collapse contents" aria-label="Expand/collapse contents" class="toc-more-items embedded material-icons collapsed ng-star-inserted" aria-pressed="false"></button></div></aio-toc><h1 translation-origin="off" id="introduction-to-components">Introduction to components<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#introduction-to-components"><i class="material-icons">link</i></a></h1><p translation-result="on"><em>组件</em>控制屏幕上被称为<em>视图</em>的一小片区域。比如，<a href="tutorial/index">教程</a>中的下列视图都是由一个个组件所定义和控制的：</p><p translation-origin="off">A <em>component</em> controls a patch of screen called a <em>view</em>. For example, individual components define and control each of the following views from the <a href="tutorial">Tutorial</a>:</p><ul><li><p translation-result="on">带有导航链接的应用根组件。</p><p translation-origin="off">The app root with the navigation links.</p></li><li><p translation-result="on">英雄列表。</p><p translation-origin="off">The list of heroes.</p></li><li><p translation-result="on">英雄编辑器。</p><p translation-origin="off">The hero editor.</p></li></ul><p translation-result="on">你在类中定义组件的应用逻辑，为视图提供支持。 组件通过一些由属性和方法组成的 API 与视图交互。</p><p translation-origin="off">You define a component's application logic—what it does to support the view—inside a class. The class interacts with the view through an API of properties and methods.</p><p translation-result="on">比如，<code>HeroListComponent</code> 中有一个 名为<code>heroes</code>的属性，它储存着一个数组的英雄数据。 <code>HeroListComponent</code> 还有一个 <code>selectHero()</code> 方法，当用户从列表中选择一个英雄时，它会设置 <code>selectedHero</code> 属性的值。 该组件会从服务获取英雄列表，它是一个 TypeScript 的构造器<a href="http://www.typescriptlang.org/docs/handbook/classes.html#parameter-properties">参数型属性</a>。本服务通过依赖注入系统提供给该组件。</p><p translation-origin="off">For example, <code>HeroListComponent</code> has a <code>heroes</code> property that holds an array of heroes. Its <code>selectHero()</code> method sets a <code>selectedHero</code> property when the user clicks to choose a hero from that list. The component acquires the heroes from a service, which is a TypeScript <a href="http://www.typescriptlang.org/docs/handbook/classes.html#parameter-properties">parameter property</a> on the constructor. The service is provided to the component through the dependency injection system.</p><code-example path="architecture/src/app/hero-list.component.ts" header="src/app/hero-list.component.ts (class)" region="class" ng-version="9.0.0-rc.11"><div style="display:none">export class HeroListComponent implements <a href="api/core/OnInit" class="code-anchor">OnInit</a> { heroes: Hero[]; selectedHero: Hero; constructor(private service: HeroService) { } ngOnInit() { this.heroes = this.service.getHeroes(); } selectHero(hero: Hero) { this.selectedHero = hero; } }</div><header class="ng-star-inserted">src/app/hero-list.component.ts (class)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/hero-list.component.ts (class)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="kwd">export</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">HeroListComponent</span><span class="pln"> </span><span class="kwd">implements</span><span class="pln"> </span><a href="api/core/OnInit" class="code-anchor"><span class="typ">OnInit</span></a><span class="pln"> </span><span class="pun">{</span><span class="pln">
  heroes</span><span class="pun">:</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">[];</span><span class="pln">
  selectedHero</span><span class="pun">:</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">;</span><span class="pln">

  </span><span class="kwd">constructor</span><span class="pun">(</span><span class="kwd">private</span><span class="pln"> service</span><span class="pun">:</span><span class="pln"> </span><span class="typ">HeroService</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="pun">}</span><span class="pln">

  ngOnInit</span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
    </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">heroes </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">service</span><span class="pun">.</span><span class="pln">getHeroes</span><span class="pun">();</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">

  selectHero</span><span class="pun">(</span><span class="pln">hero</span><span class="pun">:</span><span class="pln"> </span><span class="typ">Hero</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="kwd">this</span><span class="pun">.</span><span class="pln">selectedHero </span><span class="pun">=</span><span class="pln"> hero</span><span class="pun">;</span><span class="pln"> </span><span class="pun">}</span><span class="pln">
</span><span class="pun">}</span></code>
    </pre></aio-code></code-example><p translation-result="on">当用户在应用中穿行时，Angular 就会创建、更新、销毁一些组件。 你的应用可以通过一些可选的<a href="guide/lifecycle-hooks">生命周期钩子</a>（比如<code>ngOnInit()</code>）来在每个特定的时机采取行动。</p><p translation-origin="off">Angular creates, updates, and destroys components as the user moves through the application. Your app can take action at each moment in this lifecycle through optional <a href="guide/lifecycle-hooks">lifecycle hooks</a>, like <code>ngOnInit()</code>.</p><h2 id="component-metadata" translation-result="on">组件的元数据<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#component-metadata"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="component-metadata">Component metadata<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#component-metadata"><i class="material-icons">link</i></a></h2><img src="generated/images/guide/architecture/metadata.png" alt="Metadata" class="left" width="170" height="48"><p translation-result="on"><code>@<a href="api/core/Component" class="code-anchor">Component</a></code> 装饰器会指出紧随其后的那个类是个组件类，并为其指定元数据。 在下面的范例代码中，你可以看到 <code>HeroListComponent</code> 只是一个普通类，完全没有 Angular 特有的标记或语法。 直到给它加上了 <code>@<a href="api/core/Component" class="code-anchor">Component</a></code> 装饰器，它才变成了组件。</p><p translation-origin="off">The <code>@<a href="api/core/Component" class="code-anchor">Component</a></code> decorator identifies the class immediately below it as a component class, and specifies its metadata. In the example code below, you can see that <code>HeroListComponent</code> is just a class, with no special Angular notation or syntax at all. It's not a component until you mark it as one with the <code>@<a href="api/core/Component" class="code-anchor">Component</a></code> decorator.</p><p translation-result="on">组件的元数据告诉 Angular 到哪里获取它需要的主要构造块，以创建和展示这个组件及其视图。 具体来说，它把一个<em>模板</em>（无论是直接内联在代码中还是引用的外部文件）和该组件关联起来。 该组件及其模板，共同描述了一个<em>视图</em>。</p><p translation-origin="off">The metadata for a component tells Angular where to get the major building blocks that it needs to create and present the component and its view. In particular, it associates a <em>template</em> with the component, either directly with inline code, or by reference. Together, the component and its template describe a <em>view</em>.</p><p translation-result="on">除了包含或指向模板之外，<code>@<a href="api/core/Component" class="code-anchor">Component</a></code> 的元数据还会配置要如何在 HTML 中引用该组件，以及该组件需要哪些服务等等。</p><p translation-origin="off">In addition to containing or pointing to the template, the <code>@<a href="api/core/Component" class="code-anchor">Component</a></code> metadata configures, for example, how the component can be referenced in HTML and what services it requires.</p><p translation-result="on">下面的例子中就是 <code>HeroListComponent</code> 的基础元数据：</p><p translation-origin="off">Here's an example of basic metadata for <code>HeroListComponent</code>.</p><code-example path="architecture/src/app/hero-list.component.ts" header="src/app/hero-list.component.ts (metadata)" region="metadata" ng-version="9.0.0-rc.11"><div style="display:none">@<a href="api/core/Component" class="code-anchor">Component</a>({ selector: 'app-hero-list', <a href="api/core/Component#templateUrl" class="code-anchor">templateUrl</a>: './hero-list.component.html', providers: [ HeroService ] }) export class HeroListComponent implements <a href="api/core/OnInit" class="code-anchor">OnInit</a> { /* . . . */ }</div><header class="ng-star-inserted">src/app/hero-list.component.ts (metadata)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/hero-list.component.ts (metadata)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="lit">@</span><a href="api/core/Component" class="code-anchor"><span class="lit">Component</span></a><span class="pun">({</span><span class="pln">
  selector</span><span class="pun">:</span><span class="pln">    </span><span class="str">'app-hero-list'</span><span class="pun">,</span><span class="pln">
  </span><a href="api/core/Component#templateUrl" class="code-anchor"><span class="pln">templateUrl</span></a><span class="pun">:</span><span class="pln"> </span><span class="str">'./hero-list.component.html'</span><span class="pun">,</span><span class="pln">
  providers</span><span class="pun">:</span><span class="pln">  </span><span class="pun">[</span><span class="pln"> </span><span class="typ">HeroService</span><span class="pln"> </span><span class="pun">]</span><span class="pln">
</span><span class="pun">})</span><span class="pln">
</span><span class="kwd">export</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">HeroListComponent</span><span class="pln"> </span><span class="kwd">implements</span><span class="pln"> </span><a href="api/core/OnInit" class="code-anchor"><span class="typ">OnInit</span></a><span class="pln"> </span><span class="pun">{</span><span class="pln">
</span><span class="com">/* . . . */</span><span class="pln">
</span><span class="pun">}</span></code>
    </pre></aio-code></code-example><p translation-result="on">这个例子展示了一些最常用的 <code>@<a href="api/core/Component" class="code-anchor">Component</a></code> 配置选项：</p><p translation-origin="off">This example shows some of the most useful <code>@<a href="api/core/Component" class="code-anchor">Component</a></code> configuration options:</p><ul><li><p translation-result="on"> <code>selector</code>：是一个 CSS 选择器，它会告诉 Angular，一旦在模板 HTML 中找到了这个选择器对应的标签，就创建并插入该组件的一个实例。 比如，如果应用的 HTML 中包含 <code>&lt;app-hero-list&gt;&lt;/app-hero-list&gt;</code>，Angular 就会在这些标签中插入一个 <code>HeroListComponent</code> 实例的视图。</p><p translation-origin="off"><code>selector</code>: A CSS selector that tells Angular to create and insert an instance of this component wherever it finds the corresponding tag in template HTML. For example, if an app's HTML contains <code>&lt;app-hero-list&gt;&lt;/app-hero-list&gt;</code>, then Angular inserts an instance of the <code>HeroListComponent</code> view between those tags.</p></li><li><p translation-result="on"> <code><a href="api/core/Component#templateUrl" class="code-anchor">templateUrl</a></code>：该组件的 HTML 模板文件相对于这个组件文件的地址。 另外，你还可以用 <code>template</code> 属性的值来提供内联的 HTML 模板。 这个模板定义了该组件的<em>宿主视图</em>。</p><p translation-origin="off"><code><a href="api/core/Component#templateUrl" class="code-anchor">templateUrl</a></code>: The module-relative address of this component's HTML template. Alternatively, you can provide the HTML template inline, as the value of the <code>template</code> property. This template defines the component's <em>host view</em>.</p></li><li><p translation-result="on"> <code>providers</code>：当前组件所需的服务<a href="guide/glossary#provider">提供商</a>的一个数组。在这个例子中，它告诉 Angular 该如何提供一个 <code>HeroService</code> 实例，以获取要显示的英雄列表。</p><p translation-origin="off"><code>providers</code>: An array of <a href="guide/glossary#provider">providers</a> for services that the component requires. In the example, this tells Angular how to provide the <code>HeroService</code> instance that the component's constructor uses to get the list of heroes to display.</p></li></ul><h2 id="templates-and-views" translation-result="on">模板与视图<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#templates-and-views"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="templates-and-views">Templates and views<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#templates-and-views"><i class="material-icons">link</i></a></h2><img src="generated/images/guide/architecture/template.png" alt="Template" class="left" width="200" height="114"><p translation-result="on">你要通过组件的配套模板来定义其视图。模板就是一种 HTML，它会告诉 Angular 如何渲染该组件。</p><p translation-origin="off">You define a component's view with its companion template. A template is a form of HTML that tells Angular how to render the component.</p><p translation-result="on">视图通常会分层次进行组织，让你能以 UI 分区或页面为单位进行修改、显示或隐藏。 与组件直接关联的模板会定义该组件的<em>宿主视图</em>。该组件还可以定义一个<em>带层次结构的视图</em>，它包含一些<em>内嵌的视图</em>作为其它组件的宿主。</p><p translation-origin="off">Views are typically arranged hierarchically, allowing you to modify or show and hide entire UI sections or pages as a unit. The template immediately associated with a component defines that component's <em>host view</em>. The component can also define a <em>view hierarchy</em>, which contains <em>embedded views</em>, hosted by other components.</p><div class="lightbox"><img src="generated/images/guide/architecture/component-tree.png" alt="Component tree" class="left" width="300" height="231"></div><p translation-result="on">带层次结构的视图可以包含同一模块（NgModule）中组件的视图，也可以（而且经常会）包含其它模块中定义的组件的视图。</p><p translation-origin="off">A view hierarchy can include views from components in the same NgModule, but it also can (and often does) include views from components that are defined in different NgModules.</p><h2 id="template-syntax" translation-result="on">模板语法<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#template-syntax"><i class="material-icons">link</i></a></h2><h2 translation-origin="off" id="template-syntax">Template syntax<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#template-syntax"><i class="material-icons">link</i></a></h2><p translation-result="on">模板很像标准的 HTML，但是它还包含 Angular 的<a href="guide/template-syntax">模板语法</a>，这些模板语法可以根据你的应用逻辑、应用状态和 DOM 数据来修改这些 HTML。 你的模板可以使用<em>数据绑定</em>来协调应用和 DOM 中的数据，使用<em>管道</em>在显示出来之前对其进行转换，使用<em>指令</em>来把程序逻辑应用到要显示的内容上。</p><p translation-origin="off">A template looks like regular HTML, except that it also contains Angular <a href="guide/template-syntax">template syntax</a>, which alters the HTML based on your app's logic and the state of app and DOM data. Your template can use <em>data binding</em> to coordinate the app and DOM data, <em>pipes</em> to transform data before it is displayed, and <em>directives</em> to apply app logic to what gets displayed.</p><p translation-result="on">比如，下面是本教程中 <code>HeroListComponent</code> 的模板：</p><p translation-origin="off">For example, here is a template for the Tutorial's <code>HeroListComponent</code>.</p><code-example path="architecture/src/app/hero-list.component.html" header="src/app/hero-list.component.html" ng-version="9.0.0-rc.11"><div style="display:none">&lt;h2&gt;Hero <a href="api/common/NumberSymbol#List" class="code-anchor">List</a>&lt;/h2&gt; &lt;p&gt;&lt;i&gt;Pick a hero from the list&lt;/i&gt;&lt;/p&gt; &lt;ul&gt; &lt;li *<a href="api/common/NgForOf" class="code-anchor">ngFor</a>="let hero of heroes" (click)="selectHero(hero)"&gt; {{hero.name}} &lt;/li&gt; &lt;/ul&gt; &lt;app-hero-detail *<a href="api/common/NgIf" class="code-anchor">ngIf</a>="selectedHero" [hero]="selectedHero"&gt;&lt;/app-hero-detail&gt;</div><header class="ng-star-inserted">src/app/hero-list.component.html</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/hero-list.component.html">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="tag">&lt;h2&gt;</span><span class="pln">Hero </span><a href="api/common/NumberSymbol#List" class="code-anchor"><span class="pln">List</span></a><span class="tag">&lt;/h2&gt;</span><span class="pln">

</span><span class="tag">&lt;p&gt;&lt;i&gt;</span><span class="pln">Pick a hero from the list</span><span class="tag">&lt;/i&gt;&lt;/p&gt;</span><span class="pln">
</span><span class="tag">&lt;ul&gt;</span><span class="pln">
  </span><span class="tag">&lt;li</span><span class="pln"> *</span><a href="api/common/NgForOf" class="code-anchor"><span class="atn">ngFor</span></a><span class="pun">=</span><span class="atv">"let hero of heroes"</span><span class="pln"> (</span><span class="atn">click</span><span class="pln">)</span><span class="pun">=</span><span class="atv">"selectHero(hero)"</span><span class="tag">&gt;</span><span class="pln">
    {{hero.name}}
  </span><span class="tag">&lt;/li&gt;</span><span class="pln">
</span><span class="tag">&lt;/ul&gt;</span><span class="pln">

</span><span class="tag">&lt;app-hero-detail</span><span class="pln"> *</span><a href="api/common/NgIf" class="code-anchor"><span class="atn">ngIf</span></a><span class="pun">=</span><span class="atv">"selectedHero"</span><span class="pln"> [</span><span class="atn">hero</span><span class="pln">]</span><span class="pun">=</span><span class="atv">"selectedHero"</span><span class="tag">&gt;&lt;/app-hero-detail&gt;</span></code>
    </pre></aio-code></code-example><p translation-result="on">这个模板使用了典型的 HTML 元素，比如 <code>&lt;h2&gt;</code> 和 <code>&lt;p&gt;</code>，还包括一些 Angular 的模板语法元素，如 <code>*<a href="api/common/NgForOf" class="code-anchor">ngFor</a></code>，<code>{{hero.name}}</code>，<code>click</code>、<code>[hero]</code> 和 <code>&lt;app-hero-detail&gt;</code>。这些模板语法元素告诉 Angular 该如何根据程序逻辑和数据在屏幕上渲染 HTML。</p><p translation-origin="off">This template uses typical HTML elements like <code>&lt;h2&gt;</code> and <code>&lt;p&gt;</code>, and also includes Angular template-syntax elements, <code>*<a href="api/common/NgForOf" class="code-anchor">ngFor</a></code>, <code>{{hero.name}}</code>, <code>(click)</code>, <code>[hero]</code>, and <code>&lt;app-hero-detail&gt;</code>. The template-syntax elements tell Angular how to render the HTML to the screen, using program logic and data.</p><ul><li><p translation-result="on"> <code>*<a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> 指令告诉 Angular 在一个列表上进行迭代。</p><p translation-origin="off">The <code>*<a href="api/common/NgForOf" class="code-anchor">ngFor</a></code> directive tells Angular to iterate over a list.</p></li><li><p translation-result="on"> <code>{{hero.name}}</code>、<code>(click)</code> 和 <code>[hero]</code> 把程序数据绑定到及绑定回 DOM，以响应用户的输入。更多内容参见稍后的<a href="guide/architecture-components#data-binding">数据绑定</a>部分。</p><p translation-origin="off"><code>{{hero.name}}</code>, <code>(click)</code>, and <code>[hero]</code> bind program data to and from the DOM, responding to user input. See more about <a href="guide/architecture-components#data-binding">data binding</a> below.</p></li><li><p translation-result="on">模板中的 <code>&lt;app-hero-detail&gt;</code> 标签是一个代表新组件 <code>HeroDetailComponent</code> 的元素。 <code>HeroDetailComponent</code>（代码略）定义了 <code>HeroListComponent</code> 的英雄详情子视图。 注意观察像这样的自定义组件是如何与原生 HTML 元素无缝的混合在一起的。</p><p translation-origin="off">The <code>&lt;app-hero-detail&gt;</code> tag in the example is an element that represents a new component, <code>HeroDetailComponent</code>. <code>HeroDetailComponent</code> (code not shown) defines the hero-detail child view of <code>HeroListComponent</code>. Notice how custom components like this mix seamlessly with native HTML in the same layouts.</p></li></ul><h3 id="data-binding" translation-result="on">数据绑定<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#data-binding"><i class="material-icons">link</i></a></h3><h3 translation-origin="off" id="data-binding">Data binding<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#data-binding"><i class="material-icons">link</i></a></h3><p translation-result="on">如果没有框架，你就要自己负责把数据值推送到 HTML 控件中，并把来自用户的响应转换成动作和对值的更新。 手动写这种数据推拉逻辑会很枯燥、容易出错，难以阅读 —— 有前端 JavaScript 开发经验的程序员一定深有体会。</p><p translation-origin="off">Without a framework, you would be responsible for pushing data values into the HTML controls and turning user responses into actions and value updates. Writing such push and pull logic by hand is tedious, error-prone, and a nightmare to read, as any experienced front-end JavaScript programmer can attest.</p><p translation-result="on">Angular 支持<em>双向数据绑定</em>，这是一种对模板中的各个部件与组件中的各个部件进行协调的机制。 往模板 HTML 中添加绑定标记可以告诉 Angular 该如何连接它们。</p><p translation-origin="off">Angular supports <em>two-way data binding</em>, a mechanism for coordinating the parts of a template with the parts of a component. Add binding markup to the template HTML to tell Angular how to connect both sides.</p><p translation-result="on">下图显示了数据绑定标记的四种形式。每种形式都有一个方向 —— 从组件到 DOM、从 DOM 到组件或双向。</p><p translation-origin="off">The following diagram shows the four forms of data binding markup. Each form has a direction: to the DOM, from the DOM, or both.</p><div class="lightbox"><img src="generated/images/guide/architecture/databinding.png" alt="Data Binding" class="left" width="220" height="205"></div><p translation-result="on">这个来自 <code>HeroListComponent</code> 模板中的例子使用了其中的三种形式：</p><p translation-origin="off">This example from the <code>HeroListComponent</code> template uses three of these forms.</p><code-example path="architecture/src/app/hero-list.component.1.html" header="src/app/hero-list.component.html (binding)" region="binding" ng-version="9.0.0-rc.11"><div style="display:none">&lt;li&gt;{{hero.name}}&lt;/li&gt; &lt;app-hero-detail [hero]="selectedHero"&gt;&lt;/app-hero-detail&gt; &lt;li (click)="selectHero(hero)"&gt;&lt;/li&gt;</div><header class="ng-star-inserted">src/app/hero-list.component.html (binding)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/hero-list.component.html (binding)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="tag">&lt;li&gt;</span><span class="pln">{{hero.name}}</span><span class="tag">&lt;/li&gt;</span><span class="pln">
</span><span class="tag">&lt;app-hero-detail</span><span class="pln"> [</span><span class="atn">hero</span><span class="pln">]</span><span class="pun">=</span><span class="atv">"selectedHero"</span><span class="tag">&gt;&lt;/app-hero-detail&gt;</span><span class="pln">
</span><span class="tag">&lt;li</span><span class="pln"> (</span><span class="atn">click</span><span class="pln">)</span><span class="pun">=</span><span class="atv">"selectHero(hero)"</span><span class="tag">&gt;&lt;/li&gt;</span></code>
    </pre></aio-code></code-example><ul><li><p translation-result="on"> <code>{{hero.name}}</code>这个<a href="guide/displaying-data#interpolation"><em>插值</em></a>在 <code>&lt;li&gt;</code> 标签中显示组件的 <code>hero.name</code> 属性的值。</p><p translation-origin="off">The <code>{{hero.name}}</code> <a href="guide/displaying-data#interpolation"><em>interpolation</em></a> displays the component's <code>hero.name</code> property value within the <code>&lt;li&gt;</code> element.</p></li><li><p translation-result="on"> <code>[hero]</code><a href="guide/template-syntax#property-binding"><em>属性绑定</em></a>把父组件 <code>HeroListComponent</code> 的 <code>selectedHero</code> 的值传到子组件 <code>HeroDetailComponent</code> 的 <code>hero</code> 属性中。</p><p translation-origin="off">The <code>[hero]</code> <a href="guide/template-syntax#property-binding"><em>property binding</em></a> passes the value of <code>selectedHero</code> from the parent <code>HeroListComponent</code> to the <code>hero</code> property of the child <code>HeroDetailComponent</code>.</p></li><li><p translation-result="on">当用户点击某个英雄的名字时，<code>(click)</code> <a href="guide/user-input#binding-to-user-input-events"><em>事件绑定</em></a>会调用组件的 <code>selectHero</code> 方法。</p><p translation-origin="off">The <code>(click)</code> <a href="guide/user-input#binding-to-user-input-events"><em>event binding</em></a> calls the component's <code>selectHero</code> method when the user clicks a hero's name.</p></li></ul><p translation-result="on"><strong>双向数据绑定</strong>（主要用于<a href="guide/forms">模板驱动表单</a>中），它会把属性绑定和事件绑定组合成一种单独的写法。下面这个来自 <code>HeroDetailComponent</code> 模板中的例子通过 <code><a href="api/forms/NgModel" class="code-anchor">ngModel</a></code> 指令使用了双向数据绑定：</p><p translation-origin="off">Two-way data binding (used mainly in <a href="guide/forms">template-driven forms</a>) combines property and event binding in a single notation. Here's an example from the <code>HeroDetailComponent</code> template that uses two-way data binding with the <code><a href="api/forms/NgModel" class="code-anchor">ngModel</a></code> directive.</p><code-example path="architecture/src/app/hero-detail.component.html" header="src/app/hero-detail.component.html (ngModel)" region="ngModel" ng-version="9.0.0-rc.11"><div style="display:none">&lt;input [(<a href="api/forms/NgModel" class="code-anchor">ngModel</a>)]="hero.name"&gt;</div><header class="ng-star-inserted">src/app/hero-detail.component.html (ngModel)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/hero-detail.component.html (ngModel)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="tag">&lt;input</span><span class="pln"> [(</span><a href="api/forms/NgModel" class="code-anchor"><span class="atn">ngModel</span></a><span class="pln">)]</span><span class="pun">=</span><span class="atv">"hero.name"</span><span class="tag">&gt;</span></code>
    </pre></aio-code></code-example><p translation-result="on">在双向绑定中，数据属性值通过属性绑定从组件流到输入框。用户的修改通过事件绑定流回组件，把属性值设置为最新的值。</p><p translation-origin="off">In two-way binding, a data property value flows to the input box from the component as with property binding. The user's changes also flow back to the component, resetting the property to the latest value, as with event binding.</p><p translation-result="on">Angular 在每个 JavaScript 事件循环中处理<em>所有的</em>数据绑定，它会从组件树的根部开始，递归处理全部子组件。</p><p translation-origin="off">Angular processes <em>all</em> data bindings once for each JavaScript event cycle, from the root of the application component tree through all child components.</p><div class="lightbox"><img src="generated/images/guide/architecture/component-databinding.png" alt="Data Binding" class="left" width="358" height="219"></div><p translation-result="on">数据绑定在模板及其组件之间的通讯中扮演了非常重要的角色，它对于父组件和子组件之间的通讯也同样重要。</p><p translation-origin="off">Data binding plays an important role in communication between a template and its component, and is also important for communication between parent and child components.</p><div class="lightbox"><img src="generated/images/guide/architecture/parent-child-binding.png" alt="Parent/Child binding" class="left" width="358" height="171"></div><h3 id="pipes" translation-result="on">管道<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#pipes"><i class="material-icons">link</i></a></h3><h3 translation-origin="off" id="pipes">Pipes<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#pipes"><i class="material-icons">link</i></a></h3><p translation-result="on">Angular 的管道可以让你在模板中声明显示值的转换逻辑。 带有 <code>@<a href="api/core/Pipe" class="code-anchor">Pipe</a></code> 装饰器的类中会定义一个转换函数，用来把输入值转换成供视图显示用的输出值。</p><p translation-origin="off">Angular pipes let you declare display-value transformations in your template HTML. A class with the <code>@<a href="api/core/Pipe" class="code-anchor">Pipe</a></code> decorator defines a function that transforms input values to output values for display in a view.</p><p translation-result="on">Angular 自带了很多管道，比如 <a href="https://angular.cn/api/common/DatePipe">date</a> 管道和 <a href="https://angular.cn/api/common/CurrencyPipe">currency</a> 管道，完整的列表参见 <a href="https://angular.cn/api?type=pipe">Pipes API 列表</a>。你也可以自己定义一些新管道。</p><p translation-origin="off">Angular defines various pipes, such as the <a href="https://angular.io/api/common/DatePipe">date</a> pipe and <a href="https://angular.io/api/common/CurrencyPipe">currency</a> pipe; for a complete list, see the <a href="https://angular.io/api?type=pipe">Pipes API list</a>. You can also define new pipes.</p><p translation-result="on">要在 HTML 模板中指定值的转换方式，请使用 <a href="https://angular.cn/guide/template-syntax#pipe">管道操作符 (|)</a>。</p><p translation-origin="off">To specify a value transformation in an HTML template, use the <a href="https://angular.io/guide/template-syntax#pipe">pipe operator (|)</a>.</p><p> <code>{{interpolated_value | pipe_name}}</code></p><p translation-result="on">你可以把管道串联起来，把一个管道函数的输出送给另一个管道函数进行转换。 管道还能接收一些参数，来控制它该如何进行转换。比如，你可以把要使用的日期格式传给 <code><a href="api/common/DatePipe" class="code-anchor">date</a></code> 管道：</p><p translation-origin="off">You can chain pipes, sending the output of one pipe function to be transformed by another pipe function. A pipe can also take arguments that control how it performs its transformation. For example, you can pass the desired format to the <code><a href="api/common/DatePipe" class="code-anchor">date</a></code> pipe.</p><code-example ng-version="9.0.0-rc.11"><div style="display:none">&lt;!-- Default format: output 'Jun 15, 2015'--&gt; &lt;p&gt;Today is {{today | <a href="api/common/DatePipe" class="code-anchor">date</a>}}&lt;/p&gt; &lt;!-- fullDate format: output '<a href="api/common/WeekDay#Monday" class="code-anchor">Monday</a>, June 15, 2015'--&gt; &lt;p&gt;The date is {{today | <a href="api/common/DatePipe" class="code-anchor">date</a>:'fullDate'}}&lt;/p&gt; &lt;!-- shortTime format: output '9:43 AM'--&gt; &lt;p&gt;The <a href="" class="code-anchor">time</a> is {{today | <a href="api/common/DatePipe" class="code-anchor">date</a>:'shortTime'}}&lt;/p&gt;</div><aio-code><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="com">&lt;!-- Default format: output 'Jun 15, 2015'--&gt;</span><span class="pln">

 </span><span class="tag">&lt;p&gt;</span><span class="pln">Today is {{today | </span><a href="api/common/DatePipe" class="code-anchor"><span class="pln">date</span></a><span class="pln">}}</span><span class="tag">&lt;/p&gt;</span><span class="pln">

</span><span class="com">&lt;!-- fullDate format: output '</span><a href="api/common/WeekDay#Monday" class="code-anchor"><span class="com">Monday</span></a><span class="com">, June 15, 2015'--&gt;</span><span class="pln">

</span><span class="tag">&lt;p&gt;</span><span class="pln">The date is {{today | </span><a href="api/common/DatePipe" class="code-anchor"><span class="pln">date</span></a><span class="pln">:'fullDate'}}</span><span class="tag">&lt;/p&gt;</span><span class="pln">

 </span><span class="com">&lt;!-- shortTime format: output '9:43 AM'--&gt;</span><span class="pln">

 </span><span class="tag">&lt;p&gt;</span><span class="pln">The </span><a href="" class="code-anchor"><span class="pln">time</span></a><span class="pln"> is {{today | </span><a href="api/common/DatePipe" class="code-anchor"><span class="pln">date</span></a><span class="pln">:'shortTime'}}</span><span class="tag">&lt;/p&gt;</span></code>
    </pre></aio-code></code-example><h3 id="directives" translation-result="on">指令<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#directives"><i class="material-icons">link</i></a></h3><h3 translation-origin="off" id="directives">Directives<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#directives"><i class="material-icons">link</i></a></h3><img src="generated/images/guide/architecture/directive.png" alt="Directives" class="left" width="150" height="147"><p translation-result="on">Angular 的模板是<em>动态的</em>。当 Angular 渲染它们的时候，会根据<em>指令</em>给出的指示对 DOM 进行转换。 指令就是一个带有 <code>@<a href="api/core/Directive" class="code-anchor">Directive</a>()</code> 装饰器的类。</p><p translation-origin="off">Angular templates are <em>dynamic</em>. When Angular renders them, it transforms the DOM according to the instructions given by <em>directives</em>. A directive is a class with a <code>@<a href="api/core/Directive" class="code-anchor">Directive</a>()</code> decorator.</p><p translation-result="on">组件从技术角度上说就是一个指令，但是由于组件对 Angular 应用来说非常独特、非常重要，因此 Angular 专门定义了 <code>@<a href="api/core/Component" class="code-anchor">Component</a>()</code> 装饰器，它使用一些面向模板的特性扩展了 <code>@<a href="api/core/Directive" class="code-anchor">Directive</a>()</code> 装饰器。</p><p translation-origin="off">A component is technically a directive. However, components are so distinctive and central to Angular applications that Angular defines the <code>@<a href="api/core/Component" class="code-anchor">Component</a>()</code> decorator, which extends the <code>@<a href="api/core/Directive" class="code-anchor">Directive</a>()</code> decorator with template-oriented features.</p><p translation-result="on">除组件外，还有两种指令：<em>结构型指令</em>和<em>属性型指令</em>。 Angular 本身定义了一系列这两种类型的指令，你也可以使用 <code>@<a href="api/core/Directive" class="code-anchor">Directive</a>()</code> 装饰器来定义自己的指令。</p><p translation-origin="off">In addition to components, there are two other kinds of directives: <em>structural</em> and <em>attribute</em>. Angular defines a number of directives of both kinds, and you can define your own using the <code>@<a href="api/core/Directive" class="code-anchor">Directive</a>()</code> decorator.</p><p translation-result="on">像组件一样，指令的元数据把它所装饰的指令类和一个 <code>selector</code> 关联起来，<code>selector</code> 用来把该指令插入到 HTML 中。 在模板中，指令通常作为属性出现在元素标签上，可能仅仅作为名字出现，也可能作为赋值目标或绑定目标出现。</p><p translation-origin="off">Just as for components, the metadata for a directive associates the decorated class with a <code>selector</code> element that you use to insert it into HTML. In templates, directives typically appear within an element tag as attributes, either by name or as the target of an assignment or a binding.</p><h4 id="structural-directives" translation-result="on">结构型指令<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#structural-directives"><i class="material-icons">link</i></a></h4><h4 translation-origin="off" id="structural-directives">Structural directives<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#structural-directives"><i class="material-icons">link</i></a></h4><p translation-result="on"><em>结构型指令</em>通过添加、移除或替换 DOM 元素来修改布局。 这个范例模板使用了两个内置的结构型指令来为要渲染的视图添加程序逻辑：</p><p translation-origin="off"><em>Structural directives</em> alter layout by adding, removing, and replacing elements in the DOM. The example template uses two built-in structural directives to add application logic to how the view is rendered.</p><code-example path="architecture/src/app/hero-list.component.1.html" header="src/app/hero-list.component.html (structural)" region="structural" ng-version="9.0.0-rc.11"><div style="display:none">&lt;li *<a href="api/common/NgForOf" class="code-anchor">ngFor</a>="let hero of heroes"&gt;&lt;/li&gt; &lt;app-hero-detail *<a href="api/common/NgIf" class="code-anchor">ngIf</a>="selectedHero"&gt;&lt;/app-hero-detail&gt;</div><header class="ng-star-inserted">src/app/hero-list.component.html (structural)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/hero-list.component.html (structural)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="tag">&lt;li</span><span class="pln"> *</span><a href="api/common/NgForOf" class="code-anchor"><span class="atn">ngFor</span></a><span class="pun">=</span><span class="atv">"let hero of heroes"</span><span class="tag">&gt;&lt;/li&gt;</span><span class="pln">
</span><span class="tag">&lt;app-hero-detail</span><span class="pln"> *</span><a href="api/common/NgIf" class="code-anchor"><span class="atn">ngIf</span></a><span class="pun">=</span><span class="atv">"selectedHero"</span><span class="tag">&gt;&lt;/app-hero-detail&gt;</span></code>
    </pre></aio-code></code-example><ul><li><p translation-result="on"><a href="guide/displaying-data#ngFor"><code>*ngFor</code></a>是一个迭代器，它要求 Angular 为 <code>heroes</code> 列表中的每个英雄渲染出一个 <code>&lt;li&gt;</code>。</p><p translation-origin="off"><a href="guide/displaying-data#ngFor"><code>*ngFor</code></a>is an iterative; it tells Angular to stamp out one <code>&lt;li&gt;</code> per hero in the <code>heroes</code> list.</p></li><li><p translation-result="on"><a href="guide/displaying-data#ngIf"><code>*ngIf</code></a>是个条件语句，只有当选中的英雄存在时，它才会包含 <code>HeroDetail</code> 组件。</p><p translation-origin="off"><a href="guide/displaying-data#ngIf"><code>*ngIf</code></a>is a conditional; it includes the <code>HeroDetail</code> component only if a selected hero exists.</p></li></ul><h4 id="attribute-directives" translation-result="on">属性型指令<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#attribute-directives"><i class="material-icons">link</i></a></h4><h4 translation-origin="off" id="attribute-directives">Attribute directives<a title="Link to this heading" class="header-link" aria-hidden="true" href="guide/architecture-components#attribute-directives"><i class="material-icons">link</i></a></h4><p translation-result="on"><em>属性型指令</em>会修改现有元素的外观或行为。 在模板中，它们看起来就像普通的 HTML 属性一样，因此得名“属性型指令”。</p><p translation-origin="off"><em>Attribute directives</em> alter the appearance or behavior of an existing element. In templates they look like regular HTML attributes, hence the name.</p><p translation-result="on"><code><a href="api/forms/NgModel" class="code-anchor">ngModel</a></code> 指令就是属性型指令的一个例子，它实现了双向数据绑定。 <code><a href="api/forms/NgModel" class="code-anchor">ngModel</a></code> 修改现有元素（一般是 <code>&lt;input&gt;</code>）的行为：设置其显示属性值，并响应 change 事件。</p><p translation-origin="off">The <code><a href="api/forms/NgModel" class="code-anchor">ngModel</a></code> directive, which implements two-way data binding, is an example of an attribute directive. <code><a href="api/forms/NgModel" class="code-anchor">ngModel</a></code> modifies the behavior of an existing element (typically <code>&lt;input&gt;</code>) by setting its display value property and responding to change events.</p><code-example path="architecture/src/app/hero-detail.component.html" header="src/app/hero-detail.component.html (ngModel)" region="ngModel" ng-version="9.0.0-rc.11"><div style="display:none">&lt;input [(<a href="api/forms/NgModel" class="code-anchor">ngModel</a>)]="hero.name"&gt;</div><header class="ng-star-inserted">src/app/hero-detail.component.html (ngModel)</header><aio-code class="headed-code"><pre class="lang- prettyprint">      <button title="Copy code snippet" class="material-icons copy-button no-print ng-star-inserted" aria-label="Copy code snippet from src/app/hero-detail.component.html (ngModel)">
        <span aria-hidden="true">content_copy</span>
      </button>
      <code class="animated fadeIn"><span class="tag">&lt;input</span><span class="pln"> [(</span><a href="api/forms/NgModel" class="code-anchor"><span class="atn">ngModel</span></a><span class="pln">)]</span><span class="pun">=</span><span class="atv">"hero.name"</span><span class="tag">&gt;</span></code>
    </pre></aio-code></code-example><p translation-result="on">Angular 还有很多预定义指令既不修改布局结构（比如 <a href="guide/template-syntax#ngSwitch">ngSwitch</a>），也不修改 DOM 元素和组件的样子（比如 <a href="guide/template-syntax#ngStyle">ngStyle</a> 和 <a href="guide/template-syntax#ngClass">ngClass</a>）。</p><p translation-origin="off">Angular has more pre-defined directives that either alter the layout structure (for example, <a href="guide/template-syntax#ngSwitch">ngSwitch</a>) or modify aspects of DOM elements and components (for example, <a href="guide/template-syntax#ngStyle">ngStyle</a> and <a href="guide/template-syntax#ngClass">ngClass</a>).</p><div class="alert is-helpful"><p translation-result="on">欲知详情，参见<a href="guide/attribute-directives">属性型指令</a>和<a href="guide/structural-directives">结构型指令</a>这两章。</p><p translation-origin="off">Learn more in the <a href="guide/attribute-directives">Attribute Directives</a> and <a href="guide/structural-directives">Structural Directives</a> guides.</p></div></div></div></aio-doc-viewer></main></mat-sidenav-content></mat-sidenav-container><div class="toc-container no-print ng-star-inserted"><aio-lazy-ce selector="aio-toc"><aio-toc ng-version="9.0.0-rc.11"><div class="toc-inner no-print collapsed ng-star-inserted"><ul class="toc-list"><li class="h1 ng-star-inserted active" title="组件简介"><a href="guide/architecture-components#introduction-to-components">组件简介</a></li><li class="h2 ng-star-inserted" title="组件的元数据"><a href="guide/architecture-components#component-metadata">组件的元数据</a></li><li class="h2 ng-star-inserted" title="模板与视图"><a href="guide/architecture-components#templates-and-views">模板与视图</a></li><li class="h2 ng-star-inserted" title="模板语法"><a href="guide/architecture-components#template-syntax">模板语法</a></li><li class="h3 ng-star-inserted" title="数据绑定"><a href="guide/architecture-components#data-binding">数据绑定</a></li><li class="h3 ng-star-inserted" title="管道"><a href="guide/architecture-components#pipes">管道</a></li><li 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